The Cornea Donor Study (CDS) was designed as a prospective cohort study with the primary objective to determine whether the graft-failure rate over a 5-year follow-up period is noninferior with corneal tissue from donors older than 65 years of age compared with that from younger donors. Between January 2000 and August 2002, 80 clinical sites enrolled 1,101 subjects with a corneal disease considered to be at moderate risk for failure (principally Fuchs' dystrophy and pseudophakic corneal edema). One of 43 participating eye banks assigned a donor cornea to each subject using a web-based program to select a cornea at random from those available at the eye bank. Five-year follow up was completed in November, 2007. This application is for a continuation of the CDS to acquire valuable long-term follow-up information about the potential relationship between donor and/or patient characteristics and graft failure in a unique and established patient cohort. The proposal involves continuation of follow-up of the CDS subjects through 2012. The primary objectives of the CDS extension are to determine the overall 10-year survival rate for moderate risk grafts, which are usually related to endothelial dysfunction, and to determine whether the graft failure rate is equivalent with corneal tissue from donors older than 65 years of age compared with that from younger donors. Additional objectives include determining the predictive value of endothelial cell density in predicting graft failure and evaluating donor and recipient characteristics that may be predictive of graft failure. Procedures currently in place will be maintained throughout the next phase of the study. The CDS was designed to have a simple protocol, which approximates usual clinical practice as much as possible. Patients who consent to participate in the extended follow-up phase will be followed annually. Specular microscopy will be performed as part of an optional ancillary study for both sites and subjects. Specular images will be sent to a central reading center. While important information has been gained from the 5-year follow-up exams in 2005-2007, 10 years of follow up will provide additional information that will be of great importance to the clinician and to the patient in terms of understanding the relationship of donor age and other donor and patient factors on the likelihood of success of a cornea transplant.